third_party/WebKit/Source/core/layout/LayoutImage.h

   1 /*
   2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
   3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
   4  *           (C) 2006 Allan Sandfeld Jensen (kde@carewolf.com)
   5  *           (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
   6  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010, 2011 Apple Inc. All rights reserved.
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Library General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Library General Public License
  19  * along with this library; see the file COPYING.LIB.  If not, write to
  20  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21  * Boston, MA 02110-1301, USA.
  22  *
  23  */
  24
  25 #ifndef LayoutImage_h
  26 #define LayoutImage_h
  27
  28 #include "core/CoreExport.h"
  29 #include "core/layout/LayoutImageResource.h"
  30 #include "core/layout/LayoutReplaced.h"
  31
  32 namespace blink {
  33
  34 class HTMLAreaElement;
  35 class HTMLMapElement;
  36
  37 // LayoutImage is used to display any image type.
  38 //
  39 // There is 2 types of images:
  40 // * normal images, e.g. <image>, <picture>.
  41 // * content images with "content: url(path/to/image.png)".
  42 // We store the type inside  m_isGeneratedContent.
  43 //
  44 // The class is image type agnostic as it only manipulates decoded images.
  45 // See LayoutImageResource that holds this image.
  46 class CORE_EXPORT LayoutImage : public LayoutReplaced {
  47 public:
  48     // These are the paddings to use when displaying either alt text or an image.
  49     static const unsigned short paddingWidth = 4;
  50     static const unsigned short paddingHeight = 4;
  51
  52     LayoutImage(Element*);
  53     ~LayoutImage() override;
  54
  55     static LayoutImage* createAnonymous(Document*);
  56
  57     void setImageResource(PassOwnPtrWillBeRawPtr<LayoutImageResource>);
  58
  59     LayoutImageResource* imageResource() { return m_imageResource.get(); }
  60     const LayoutImageResource* imageResource() const { return m_imageResource.get(); }
  61     ImageResource* cachedImage() const { return m_imageResource ? m_imageResource->cachedImage() : 0; }
  62
  63     HTMLMapElement* imageMap() const;
  64     void areaElementFocusChanged(HTMLAreaElement*);
  65
  66     void setIsGeneratedContent(bool generated = true) { m_isGeneratedContent = generated; }
  67
  68     bool isGeneratedContent() const { return m_isGeneratedContent; }
  69
  70     inline void setImageDevicePixelRatio(float factor) { m_imageDevicePixelRatio = factor; }
  71     float imageDevicePixelRatio() const { return m_imageDevicePixelRatio; }
  72
  73     void intrinsicSizeChanged() override
  74     {
  75         if (m_imageResource)
  76             imageChanged(m_imageResource->imagePtr());
  77     }
  78
  79     const char* name() const override { return "LayoutImage"; }
  80
  81 protected:
  82     bool needsPreferredWidthsRecalculation() const final;
  83     LayoutBox* embeddedContentBox() const final;
  84     void computeIntrinsicRatioInformation(FloatSize& intrinsicSize, double& intrinsicRatio) const final;
  85
  86     void imageChanged(WrappedImagePtr, const IntRect* = nullptr) override;
  87
  88     void paint(const PaintInfo&, const LayoutPoint&) final;
  89
  90     void layout() override;
  91     bool updateImageLoadingPriorities() final;
  92
  93     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectLayoutImage || LayoutReplaced::isOfType(type); }
  94
  95     void willBeDestroyed() override;
  96
  97     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
  98
  99 private:
 100     bool isImage() const override { return true; }
 101
 102     void paintReplaced(const PaintInfo&, const LayoutPoint&) override;
 103
 104     bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect& localRect, unsigned maxDepthToTest) const final;
 105     bool computeBackgroundIsKnownToBeObscured() final;
 106
 107     bool backgroundShouldAlwaysBeClipped() const override { return true; }
 108
 109     LayoutUnit minimumReplacedHeight() const override;
 110
 111     void notifyFinished(Resource*) final;
 112     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) final;
 113
 114     bool boxShadowShouldBeAppliedToBackground(BackgroundBleedAvoidance, InlineFlowBox*) const final;
 115
 116     void invalidatePaintAndMarkForLayoutIfNeeded();
 117     void updateIntrinsicSizeIfNeeded(const LayoutSize&);
 118     // Update the size of the image to be rendered. Object-fit may cause this to be different from the CSS box's content rect.
 119     void updateInnerContentRect();
 120
 121     // This member wraps the associated decoded image.
 122     //
 123     // This field is set using setImageResource above which can be called in
 124     // several ways:
 125     // * For normal images, from the network stack (ImageLoader) once we have
 126     // some image data.
 127     // * For generated content, the resource is loaded during style resolution
 128     // and thus is stored in ComputedStyle (see ContentData::image) that gets
 129     // propagated to the anonymous LayoutImage in LayoutObject::createObject.
 130     OwnPtrWillBePersistent<LayoutImageResource> m_imageResource;
 131     bool m_didIncrementVisuallyNonEmptyPixelCount;
 132
 133     // This field stores whether this image is generated with 'content'.
 134     bool m_isGeneratedContent;
 135     float m_imageDevicePixelRatio;
 136 };
 137
 138 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutImage, isLayoutImage());
 139
 140 } // namespace blink
 141
 142 #endif // LayoutImage_h